Unloader for single-acting compressors.



No. 834,626. PATENTED OCT. 30, 1906. P. VAN D. LONGACRB. l UNLOADER FOR SINGLE ACTING COMPRESSORS.

v APPLICATION ILED NOV.23.1904.

2 SHEETS-SHEET 1.

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PATENTED OCT. 30, 1906.

F. VAN D. LONGAGRB. UNLOADBR POR SINGLE ACTING GOMPRBssoRs.

APPLIGATION IILED NOV.23,1904.

2 SHEETS-SHEET 2,

UNITED sTATEs PATENT oFFICE.

"FREDERICK VAN DUZEE.LCNGACREv oF NEW YORK, N. Y., ASSIGNOR To INGERsoLL-RAND COMPANY. yoF NEWYCRK, N. .Y., A CoRFoRATioN C y oF NEvir JERSEY.` l

lUNLOAIDEE Fon AslNew.l-z-arrlrlae. coMPnEssoBs.'

To all whom lit -may concern,.-

:Be it known that I, FREDERICK VAN VDUZERv LONGACRE, a citizen of the United States, and a resident of the borou h of Manhattan, in the city and State of ew York, havei'nvented new and useful Improvements t in Unloaders for Single-Acting Compressors,

of which the following is a specification.

TheA object v`of this invention is to provide certain improvements in the construction,

`form, and arrangement of the several parts between the pressure-port of the discharge# valve andthe receiver. IFig. 2 isasimilar view showing the |positions of the parts'when the electromagnet is energized and communication is established between the pressure-port of the discharge-valve andthe exhaust-port leading to the atmosphere. Fig. 3 is a dia` grammatic view showin lan electrical system suitable for'use in contro ling the operation of the unloader-electromagnet, the said view including portions of a one stage air compressor, a receiver, the unloader, and the ipe connectionsy between 'the discharge va ves,

receiver, and unloader; and Figlfi is a-detail View in section of one ofthe disc arge-valves.y

In this type of unloader pressure is established back of the discharge-valve by openin communicationfrom the receiver to the bac of the discharge-valve, and the dischar evalve is unloaded yat any desired moment y the energiz'ation of an electromagnet whic will operate a valve and open communication l from the space back of` the discharge-valve to the atmosphere, which valve at thevsame time will close the lreceiver pressure-port.

The electromagnet comprises a suitable bracket 1, the coil 2, and the core 3.

The electromagnet herein represented is of the solenoid type, and the core 3 is fitted to slide vertically in a tube 4, the lower end of which is provided with a removable cap 5,

f Specification of Letters Patent. l Application iiledN-oveinber 23, 1964. Serial No. 234.011.

x the said chamber. vided with a pressure-port 9, which is adapted their pipes 25 are shown as connected 'Patented oct. 30,1906.

which cap serves to support the core 3 when `the ma net is denergized. v

The racket 1 of the electromagnet is surmounted by the valve-box 6, the vsaid valvebox having achamber 7, the up er end oi.V which isclosed by a top cap 8, w 'ch has a screw-threaded engagement with the walls of This top cap 8 `is pro.-

yto be connected to a receiver 22 through a pipe 23. A suitable valve-seat 1() is provlded through the side ofthe valve-box, which port -11 is arran ed to be connected to the space back of a ischarge-valve 24 of a one-stage at the inner end of the port 9. A pressureport 11` opens into the valve-chamber r7 air-compressor 26 through a pipe 25. In the present instance two discharge-valves 24 and to the common ressure-port 11. A12 is A ring seated in t e bottom of the valve-chamber 7, 'v l the bore of which ring forms an exhaust-port 13, which communicates with-a central exhaust-chamber 14, from which transverse jy ports 15 lead to the exterior ofthe valve-box.

The mouth' of the port 13 is provided with a valve-seat 16.

j The ball-valve is denoted by 17'and normally restsupon its seat 16, leaving communication. open between the receiver pressureport and the discharge-valve pressure-port.

- The valve-box 6 is provided with a stepped hollow, depending portion 18 19, the larger ortion 18 being fitted to the top of the- `racket land the 'smaller' portion 19, being extended into the electromagnet 2 and hav- 1 ing a screw-threaded engagement with the top of the core-tube 4.

A rod 20 rests upon the top of the core 3 and extends with an easy sliding t upwardly through the valve-box into engagement wit the bottom of the valve 17,.l It is desirable that the upward movement of the rod 20v and core 3 when theelectromagnet 2 is energized be retarded to a certain extent, so as to prevent a too'rapid shifting of the valve 17.

This object is accomplished by making the valve-box 6 of some magnetic material-such, for instance, asmagnetic ironso that when the electromagnet 2Kis energized a certain amount of ma netism lis imparted to the' valve-box 6. i he attraction of the rod 20 to port, an exhaust-port and a dischar e-va alternately opening and closin the pressureV su ply and exhaust ports to t e dischargeva ve ort. i y

8. air-compressor, a discharge-valve therefor andlan unloader comprising a valvebox, its chamber having a pressure-supply ve gort in communication with the bac of the iseharge-valve, a' valve for 4o ening and closing communication from t e pressure supply and exhaust ports to the dischargeva ve port, an eleotromagnet of the solenoid type having a centrally-arranged tube, a core t erein, a removable bottom cap engaging the tube for limiting the downward movement of the core and a rod interposed between the top of the core and valve for bringing the valve under the control of the operation of the electromagnet.

-my invention I have signed 9. An air-compressor, avdischarge-valve therefor, a receiver and an unloader comprising a valve-box, its. chamber having a pressure-port in communication with the receiVer, a' discharge-.valve port in communication withithe backl ofthe dischar e-valve, and an exhaust-port, a ball-valve or alternately openingj and closing communication from the receiver pressure-port and'exhaustport to the discharge-valve port and electrically-controlledl means for operating the valve.

In testimony that I claim the foregoing as my name7 in resence of two witnesses, this 14th day of ovember, 1904. i

FREDERICK VAN DUZER LONGACR,

Witnesses: o

FREDK.' HAYNES, HENRY THIEME. 

